US4013355A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Notch filter for color transparency copying machines
Assignee: Xerox Corp
•
Filing: 1975-07-30
•
Granted: 1977-03-22
•
Expires: 1995-07-30
Abstract
Abstract An electrophotographic printing machine in which color transparencies are reproduced. The printing machine includes a notch filter which transmits blue and green light images of the color transparency therethrough while blocking a portion of the red light image from passing therethrough.
Inventors
- 👤 Louis D. Mailloux
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:43
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/01; G03G15/0105; G03G15/011
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
135 words
An electrophotographic printing machine for reproducing a color transparency, including: a photoconductive member; means for producing a charge having a substantially uniform level on at least a portion of said photoconductive member; means for forming a light image of the color transparency; means for modulating the light image to produce a halftone light image; means for filtering successive light images of the color transparency to form successive blue, red, and green light images thereof; and a notch filter interposed into the optical path to block a portion of the red light image while transmitting the blue and green light images therethrough, each light image transmitted through said notch filter passing through said filtering means and said modulating means to irradiate the charged portion of said photoconductive member recording thereon successive single color electrostatic latent images.
Claim 2
Dependent Claim
135 words
An electrophotographic printing machine for reproducing a color transparency, including: a photoconductive member; means for producing a charge having a substantially uniform level on at least a portion of said photoconductive member; means for forming a light image of the color transparency; means for modulating the light image to produce a halftone light image; means for filtering successive light images of the color transparency to form successive blue, red, and green light images thereof; and a notch filter interposed into the optical path to block a portion of the red light image while transmitting the blue and green light images therethrough, each light image transmitted through said notch filter passing through said filtering means and said modulating means to irradiate the charged portion of said photoconductive member recording thereon successive single color electrostatic latent images.
Claim 3
Dependent Claim
67 words
A printing machine as recited in claim 1, further including: a supporting member; an opaque document positioned on said supporting member; and means for exposing the charged portion of said photoconductive member to a light image of said opaque document recording thereon a combined electrostatic latent image of the single color electrostatic latent image of the color transparency and the electrostatic latent image of said opaque document.
Claim 4
Dependent Claim
24 words
A printing machine as recited in claim 2, wherein said forming means projects a light image of the color transparency through said supporting member.
Claim 5
Dependent Claim
32 words
A printing machine as recited in claim 3, wherein said opaque document includes a composition frame defining an opaque border extending outwardly from the color transparency image transmitted through said supporting member.
Claim 6
Dependent Claim
35 words
A printing machine as recited in claim 3, wherein said forming means includes a slide projector located on the printing machine for projecting an image of the color transparency disposed therein through said supporting member.
Claim 7
Dependent Claim
31 words
A printing machine as recited in claim 5, wherein said supporting member includes: a transparent platen having said opaque document disposed thereon; and a Fresnel lens mounted on said opaque document.
Claim 8
Dependent Claim
24 words
A printing machine as recited in claim 6, wherein said modulating means inlcudes a screen interposed between said Fresnel lens and said opaque document.
Claim 9
Dependent Claim
23 words
A printing machine as recited in claim 7, wherein said screen includes a transparent sheet having a plurality of opaque, spaced dots thereon.
Claim 10
Dependent Claim
47 words
A printing machine as recited in claim 2, wherein said exposing means includes: a light source arranged to illuminate said opaque document positioned on said supporting member; and lens means for receiving the light rays from the combined image of the color transparency and said opaque document.
Claim 11
Dependent Claim
66 words
A printing machine as recited in claim 2, further including: means for developing each electrostatic latent image recorded on said photoconductive member with differently colored toner particles; means for transferring the toner particles adhering to each of the electrostatic latent images to the sheet of support material in superimposed registration with one another; and means for fusing the toner particles to the sheet of support material.
Claim 12
Dependent Claim
62 words
A printing machine as recited in claim 2, wherein said notch filter has a transmittance of less than about 10% from a wavelength of about 580 nanometers to about 620 nanometers with the transmittance being greater than about 70% from a wavelength of about 380 nanometers to about 560 nanometes and from a wavelength of about 635 nanometers to about 700 nanometers.
Claim 13
Dependent Claim
140 words
A printing machine as recited in claim 11, wherein said filtering means includes: a blue filter having a transmittance less than 10% from a wavelength of about 480 nanometers to about 630 nanometers with the transmittance being greater than 70% from a wavelength of about 375 nanometers to about 470 nanometers; a red filter having a transmittance less than 10% from a wavelength of about 350 nanometers to about 560 nanometers with the transmittance being greater than 70% from a wavelength of about 580 nanometers to about 700 nanometers; and a green filter having a transmittance less than 10% from a wavelength of about 375 nanometers to about 470 nanometers and from a wavelength of about 570 nanometers to about 700 nanometers with the transmittance being greater than 70% from a wavelength of about 510 nanometers to about 550 nanometers.
References Cited (Backward Citations)
US3248216A
Cited
US3547533A
Cited
US3642370A
Cited
US3517596A
Cited
US3561866A
Cited
US3936173A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-03-21 | 1980-09-20 | 1981-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-21 | 1984-09-20 | 1985-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-21 | 1988-09-20 | 1989-03-22 | $7700.00 | Window Closed / Lapsed |